Forget the traditional newborn cries that come out of the maternity ward; when a baby is born at Magee-Womens Hospital in Pittsburgh, you’re more likely to hear the soothing tones of someone singing.

This is how Dr. Carey Andrew-Jaja welcomes his littlest patients into the world, singing from a repertoire that ranges from their very first birthday song to Louis Armstrong’s “What a Wonderful World,” ABC News reports.

“I’ve delivered about 8,000 babies, and I must have sung at least to 6,000 or 7,000 of them,” Andrew-Jaja told the news site.

According to ABC, Andrew-Jaja is just the inheritor of the adorable tradition, learning it as a young resident from a physician who sang to newborns. “He was about to retire. He asked me to continue the tradition,” Andrew-Jaja said. “And I’ve done it ever since.”

The little tradition has caught on, and some patients admit that they would be disappointed if he did not greet their special bundle with a song, too.

“When I’m singing to those babies, I think I’m singing to a future important person. That’s the credit I give to all of them. So to me it’s a wonderful thing in my hand, the miracle of life, and the rest of it is that it’s a beautiful world we live in,” the doctor added in a video posted by the University of Pittsburgh Medical Center on YouTube.